README.md -> fix build status link (#792)

README.md -> fix build status link

README.md

@@ -1,6 +1,6 @@
 # go-mysql-server
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
-<a href="https://travis-ci.org/src-d/go-mysql-server"><img alt="Build Status" src="https://travis-ci.org/src-d/go-mysql-server.svg?branch=master" /></a>
+<a href="https://travis-ci.com/src-d/go-mysql-server"><img alt="Build Status" src="https://travis-ci.com/src-d/go-mysql-server.svg?branch=master" /></a>
 <a href="https://codecov.io/gh/src-d/go-mysql-server"><img alt="codecov" src="https://codecov.io/gh/src-d/go-mysql-server/branch/master/graph/badge.svg" /></a>
 <a href="https://godoc.org/github.com/src-d/go-mysql-server"><img alt="GoDoc" src="https://godoc.org/github.com/src-d/go-mysql-server?status.svg" /></a>
 [![Issues](http://img.shields.io/github/issues/src-d/go-mysql-server.svg)](https://github.com/src-d/go-mysql-server/issues)